How horrifying that you have to worry about your dog being stolen.
Mine are never outside without me. I don't have a fenced yard (our CCR prohibits them) so they don't go out without a harness on. There are so many eagles, hawks and coyotes (as well as a few bear) in the area where I live. I have seen the hawks pick up and carry off jack rabbits who were way bigger then my two dogs.
Here is a site I found :
http://www.idausa.org/campaigns/theft/protectpet.html